What?
- Bitterness, browning of white wine (symptoms in mead should be of the
same kind.)
Why?
- Reaction with the oxygen of the air.
What to do?
- No solution [V3].
- Add sulphite and vitamin C (anti-oxidants) [V4].
- Use casein to treat the color problem.
How to prevent?
- Keep contacts with air to a minimum (little air space in carboys and
bottles, no splashing of the must when racking, avoid porous corks).
- Use antioxidants (sulfite and vitamin C).
- Maintain a low pH [V3].
- Maintain a low enough temperature [B2, V3].
Why?
- Fermentation inside the bottles because the mead has been bottled before
the fermentation was done or fermentation restarted inside the bottles.
What to do?
- Uncork all bottles from the same batch and pour the content into a
carboy with an airlock.
- If the mead is sparkling on purpose, use bottles suitable for the pressure
of sparkling meads (Champagne bottles).
How to prevent?
- Wait until the fermentation is done before bottling.
- Concerning sweet meads, prevent the fermentation from restarting using
SO2 and sorbic acid (see Chemicals.)
What?
- White crystals drop to the bottom of the fermentation vessel when it
is kept at a low temperature.
Why?
← potassium bitartarate
- Tartaric acid reacts with K+ ions (potassium ions) and forms
potassium bitartarate (cream of tartar, left figure) that is not much soluble
in the water-ethanol mixture at low temperature.
What to do?
- Rack, dealing with crystals as if they were lees.
- Let the temperature go back up and the crystals will vanish (this phenomenon
is fully reversible).
- Nothing: the crystals will stay at the bottom of the bottle and will
not bother anybody.
How to prevent?
- Do not use tartaric acid.
- Make this phenomenon happen: purposefully cool down the must then rack.
The problem will not happen again when a bottle is put in the fridge. This
is what winemakers call "cold stabilization".
What?
- Mead is not clear at all or there are particles in suspension. Flavor
and nose are not abnormal.
Why?
- There are yeast cells or proteins in suspension in the mead.
What to do?
- Wait and rack. This will all flocculate naturally. If symptoms remain,
add fining agents and rack.
How to avoid?
- This is a natural phenomenon, it can be attenuated though if proteins
are removed when honey is sanitized.
What?
- The mead is not clear or particles can be seen. Furthermore, odor and/or
flavor has an anomaly.
Why?
What to do?
- First, how bad is it hurt? Some bacteria do not do much harm:
it's possible that the mead still taste good and be safe.
How to avoid?
- Keep contact with air to a minimum (to avoid introducing bacteria and
providing it with the oxygen it needs).
- Reach an alcohol content of at least 12-14 % (24-28 proof). Concerning
sherry (whose fermentation is partly aerobic), reach an alcohol content
of 14-15 % (28-30 proof) before aerating to form the flor [V6].
- Sulphite [V6].
- Bacteria usually do not like low pH.
May 28th 2002
